@mixin bg-image($url) {
  background-image: url($url + "@2x.png");
  @media (-webkit-min-device-pixel-ratio: 3),(min-device-pixel-ratio: 3) {
    background-image: url($url + "@3x.png");
  }
  -webkit-background-size: 100% 100%;
  background-size: 100% 100%;
}

@mixin border-bottom-1px ($color) {
  position: relative;
  &:after {
    content: '';
    display: block;
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    border-top: 1px solid $color;
  }
  @media (-webkit-min-device-pixel-ratio: 1),(min-device-pixel-ratio: 1) {
    &:after {
      -webkit-transform: scaleY(1);
      transform: scaleY(1);
    }
  }
  @media (-webkit-min-device-pixel-ratio: 1.5),(min-device-pixel-ratio: 1.5) {
    &:after {
      -webkit-transform: scaleY(0.7);
      transform: scaleY(0.7);
    }
  }
  @media (-webkit-min-device-pixel-ratio: 2.0),(min-device-pixel-ratio: 2.0) {
    &:after {
      -webkit-transform: scaleY(0.5);
      transform: scaleY(0.5);
    }
  }
}
